Only five per cent of secondary schools are considering joining the Government's controversial education "revolution", according to a survey published yesterday.
The Association of School and College Leaders said its poll showed support for the Government's proposed "trust schools" was "very weak" among headteachers.
Nearly three-quarters (73 per cent) of school lead-ers surveyed said they were unlikely or "definitely not" considering joining the trust schools scheme.
ASCL general secretary John Dunford said: "This poll shows clearly what we have been saying from the beginning, which is that trust status does not offer any new real independence for schools.
"However, we would welcome trust schools if their role was to promote partnerships among schools.
"The proposal for individual schools to acquire trust status sends the message that schools should work in isolation, at the expense of other local schools."
MPs should make sure that all trust schools are obliged to collaborate with other schools, he said.
ASCL member Alan Sedgley, from Liskeard School and College in Cornwall, said: "We do not need trust status.
"We are able to work with other schools and with colleges and businesses without further legislation."
Bill Kelly, from Ibstock Community College, Leicestershire, added: "Overall, this is a Bill to encourage competition between schools rather then collaboration.
"From this one view alone, it is a backward step."
Mick Brookes, general secretary of the National Association of Head Teach-ers, warned that the Bill could lead to a "free-for-all" in school admissions.
He said the political "shambles" over the reforms was "an absolute distraction from the real agenda".
"What the Bill may well usher in is the opportunity for some schools to conduct an admissions free-for-all that will inevitably disad-vantage the very children we need to protect," he said.
A spokesman for the Department for Education argued that the poll showed that 26 per cent of heads were considering backing the plan.
If this were replicated nationally, it would mean 800 secondaries were considering becoming trust schools, he said.